1. Field of the Invention
The present invention relates to a cleaning substrate and a cleaning method, and in particular relates to a cleaning substrate that cleans the interior of a processing chamber in a substrate processing apparatus and a cleaning method using the cleaning substrate.
2. Description of the Related Art
A substrate processing apparatus, for example, a plasma processing apparatus has a processing chamber (chamber) in which a wafer as a substrate is accommodated, and a process gas is supplied into the chamber to subject the wafer to plasma processing, for example, etching processing. In the chamber, when plasma processing is carried out, reaction product arising from the reaction of the process gas is produced, and part of the reaction product floats as particles (foreign matter). If the floating particles become attached to a surface of a wafer, short-circuiting of wiring will occur in a product manufactured from the wafer, resulting in decreasing the yield of semiconductor devices ultimately manufactured.
Moreover, if the plasma processing is repeatedly carried out in the chamber, deposit becomes attached to a wall of the chamber and surfaces of component parts. The deposit cannot be completely removed by dry cleaning, and is thus removed by carrying out wet cleaning on a regular basis. In the wet cleaning, the chamber is opened to the atmosphere. When the chamber is opened to the atmosphere, moisture in the atmosphere becomes attached to the wall of the chamber and the surfaces of component parts. The moisture (foreign matter) attached to the wall of the chamber and the surfaces of component parts gradually evaporates and diffuses into the chamber and thus adversely affects the plasma processing.
Conventionally, to remove such foreign matter (particles and moisture) from the chamber, maintenance of the chamber such as evacuation of the chamber using an exhaust system that exhausts gas inside the chamber is carried out (see, for example, the specification of Japanese Patent Application No. 2007-092380).
However, because the interior of the chamber in the substrate processing apparatus is required to be cleaned to a high level, the above described maintenance has to be carried out for a long time period. For this reason, there is the problem that the operation of the substrate processing apparatus has to be stopped for a long time period, resulting in the operating rate of the substrate processing apparatus decreasing.